Portable grease guns are used throughout industry to provide a supply of pressurized grease to lubricate vehicles and myriad types of machinery. In the typical portable hand held grease gun, a grease gun body includes a screw mounting to which a grease “barrel”(a tube having one closed end and an open end) containing a quantity of grease or a grease cartridge may be attached to provide a source of grease for the grease gun. When the grease within the cartridge is exhausted, the barrel may be unmounted and a new cartridge inserted and the barrel remounted to the screw mounting of the grease gun body. Grease guns of this type are limited to use with a self contained grease barrel mounted to the grease gun body and carried with it. Such grease guns are useful when the user will need to move around a wide area to lubricate equipment zerks.
Other grease guns are provided with a coupling to a flexible hose connected to a grease supply which may rest on the ground or another surface and need not be carried by the user. Typical of such a grease supply is a container of bulk grease such as a pail or bucket or keg equipped with a hand operated or foot operated pump. As grease is needed in the grease gun body, the user pumps a charge of grease from the grease pail by operating the manual pump, thereby driving a supply of grease into the compression chamber of the grease gun. Existing grease guns of this nature allow for coupling to a grease hose only. This type of grease gun body is useful when the user may remain in a limited area while applying lubricating grease.
Existing hand held portable grease guns provided with removable grease gun barrel are provided with output check valves which resist pressure in the pressure chamber below about 25 psi so that grease under approximately 15 psi in the grease barrel will not discharge through the output nozzle. Resupply of the barrel through the standard resupply port on the grease gun body is limited to low pressure sources so that grease entering grease gun body through the resupply port will not be forced past the output check valve associated with the output nozzle.
A need exists for a versatile grease gun body which may be supplied by a grease barrel mounted on the gun body or by a larger supply of grease carried in a grease pail, barrel or keg and supplied to the grease gun barrel by a hose which may be coupled to the grease gun body.
A further need exists for a versatile grease gun which can be supplied through the standard resupply port at pressures exceeding 25 psi such as through a hose coupled to a grease reservoir pressurized by a foot pump.
The foregoing problems are addressed by the present grease gun invention.